package com.shen.start;

import java.util.Scanner;

public class Min {
    public static void main(String[] args) {
        Scanner console = new Scanner(System.in);
        int m = console.nextInt();
        int n = console.nextInt();
        int result = getCM(m, n);
        System.out.println(result);
    }

    public static int getCM(int m, int n){

        //write your code here......
        int max = Math.max(m,n);
        for(int i=max; i<=m*n;i++){
            if(i%m==0 && i%n==0){
                return i;
            }
        }
        return -1;
    }


}
